Commentary: After the aluminum rush: restoring the Amazon rainforest

Can the degraded land of the Amazon rainforest be salvaged by large-scale landscape restoration? Is it really possible to rebuild ecological integrity and enhance the lives of local communities in a sustainable way?

To delve deeper into these questions, in late 2011 I took a two-month sabbatical from my position as a mining and environment consultant specializing in mine closure and post-mining regeneration at Wardell Armstrong International. It was a personal odyssey to explore world-class landscape restoration, where I came face to face with some of the biggest environmental challenges in international mining, and found some equally surprising answers.

Supported by a fellowship from the Winston Churchill Memorial Trust, I travelled from mountaintop-removal coal mines in Appalachia to the southern tip of South America, and from the Everglades, Costa Rica and the Galapagos Islands to Atlantic rainforests and the farmlands and logged forests in Chilean and Argentine Patagonia.

But it was in Brazil — a country determined to use its vast natural resources to help lift its citizens out of poverty — that I was best able to assess some of the biggest impacts of international mining operations, as well as some of the most pioneering restoration measures to be found anywhere in the world.

Brazil’s rapidly growing mining industry extracts metals and minerals across the Amazon. The typical image of mining here is one of thousands of garimpeiros causing environmental and human damage as they scrape gold and gemstones from the harsh earth. But while such scenes do exist, the real national wealth from Brazilian mining is produced by some of the world’s biggest mines.

My visit took in two of the largest aluminum mines in the Amazon: Mineracao Rio do Norte’s (MRN) Trombetas and Alcoa’s Juruti.

The Trombetas mine is located on the Trombetas tributary of the Amazon River, and ranks as the largest aluminum mine in the world.

Mining began in the 1970s when there was little but rainforest and small, scattered communities. Today there’s an enormous surface mine and a town of a few thousand people, surrounded by the Saraca-Taquera National Forest protected area.

A legal obligation to restore the forest has been underway since 1984. Up to 2011, 9 million trees have been planted over 45 sq. km to recreate high biodiversity rainforest.

The Juruti mine, on the south side of the Amazon, is a similar bauxite deposit boasting 700 million tonnes of ore. The development is much newer, however, with mining beginning in the last couple of years and set to last until at least the end of the century.

Both operations strip-mine the expansive deposits just a few metres below the roots of the rainforest. First, the forest is cleared and the commercial timber is stockpiled. Then the 5 cm thick topsoil and the 8- to 12-metre-thick overburden are scraped off separately and stockpiled for later use in reclamation. This reveals the red bauxite below, which is excavated. The topsoil is then put back and planted with rainforest tree seedlings.

In fact, rainforest restoration begins even before mineral extraction starts. Wildlife monitoring is set-up two years before and continues during forest clearance. Rescue teams made up of trained local contractors scour the forest before clearance to remove and translocate slow-moving animals such as sloths and tortoises to previously restored forest areas. They also save important plant specimens and the nests of stingless bees that are vital for pollination.

The restoration team’s goal is to regrow the jungle so that it’s as close to the original as possible. Working in collaboration with Brazilian scientific institutions, Trombetas has been researching how to best do this for over 30 years, using a systematic nursery and field research strategy.

Since 1997, 50 master’s and 25 PhD theses have investigated the developing ecology of these forests. The newer Juruti operation, on the other hand, is building on a generation of Trombetas forest-restoration knowledge.

Of the 180 tree species in the local forest at Trombetas, about 100 are chosen for replanting. Selection is based on their speed of growth for soil protection, their ability to attract animals to import seeds from outside the area and their use to people.

Around Juruti the jungle contains about 460 tree species, of which currently only 30 species — mainly pioneer ones — are planted in the restoration schemes.

While Trombetas’ restoration work has provided the template for Juruti’s approach, there’s still a great deal of crossover. Both mines, working with Brazilian scientists, are refining their rehabilitation practices.

The latest initiative involves loose-tipping translocated topsoil off the backs of trucks and leaving it uncompacted. The regular rain of the area washes these piles down to cover the surrounding subsoil into which trees are then planted. Since no spreading is involved, this method improves tree establishment with fewer heavy vehicle movements and lower fuel costs and emissions.

A favourite species for economic reasons is the Brazil nut tree. The tree doesn’t do well in plantations and will only grow in areas of standing rainforest. At Trombetas, 12 local village families help collect seeds and raise seedlings to augment the half-million produced every year by MRN’s nursery.

Although the restoration team constantly push to improve their success rate of around 70%, the oldest planted areas at Trombetas are now becoming indistinguishable to the casual observer from the rest of the forest. In the very first areas planted in the early 1980s, the translocated stingless bee hives are full of life, epiphytes have been reintroduced from more recently cleared areas and a Brazil nut tree is already a 40-metre giant.

Even at Juruti, trees planted less than three years ago in a small pilot area already stand at twice a person’s height. The shade-inducing canopy is closing. Light-loving weeds are shaded out. Forest understorey plants are gaining a toehold. New trees are coming in, spread from the feces of animals attracted to the newly planted forest areas. Slowly, the rainforest is recreating its own self-supporting web of life.

Seeing such world-class accomplishments should go some way to offset the general public perception of large-scale destruction and devastation. Concerned and talented people are making genuine, inspired efforts to regrow the forests and provide new environmental, social and economic opportunities in a rapidly changing world.

— Peter Whitbread-Abrutat holds a PhD in Mining Environmental Science from the University of Exeter, and is a mining environment and community specialist at U.K.-based independent engineering consultancy Wardell Armstrong International. He can be reached at pabrutat@wardell-armstrong.com .

With a heritage dating back more than 175 years, Wardell Armstrong specializes in mineral resource development and management, and helps tackle some of the world’s most pressing environmental challenges like renewable energy generation, waste management and environmentally responsible mining.
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